Apple sold 47.8 million iPhones in the last quarter of 2012 and its revenues rose to \$54.5bn but figures slightly missed targets.
Shares of the computing giant fell in after-hour trade, at one point plunging more than 10%.
Some analysts had expected iPhone sales to be around 50 million and revenues to be slightly higher.
The results are likely to rekindle questions over what Apple has in its product pipeline, and what it can do to attract new sales and maintain its growth trajectory.
It was the third quarter that Apple had missed revenue expectations.
Competition from Samsung and signs that the smartphone market may be close to saturation have slowed Apple’s growth.
Questions remain over the company’s ability to innovate after the death of Steve Jobs.
But chief executive Tim Cook said he was “thrilled” with the figures and insisted the company continued to focus on innovation.
“We’re thrilled with record revenue of over \$54bn and sales of over 75 million iOS devices in a single quarter,” Mr Cook said.
“We’re very confident in our product pipeline as we continue to focus on innovation and making the best products in the world.”
Apple also sold 22.9 million iPads in the quarter, in line with expectations.